You don't have to file taxes in Germany except if you and your spouse are filing together or if you are self employed. Everything else is being handled by your employer.
If you want to get some of your pre-paid taxes back, you will have to file but the tax office doesn't care if you don't.
To be honest I don't know how it is now, but I remember my parents always having an accountant because it was just so much easier to deal with this, and they were a teacher and psychologist (not self employed), without any significant additional income.
Having an accountant do it in that situation is so not worth it. I know my parents also used one for way too long. So easy with tax software and with the government software you don't even have to pay for the software any longer.
Fun fact, they called the government provided tax software ELSTER which in German is also the name of a bird (Eurasian magpie) which is also known as the "thieving magpie". Who said the government didn't have a sense of humor!
If you want to get some of your pre-paid taxes back, you will have to file but the tax office doesn't care if you don't.